Yasas Fernando

Projects

Selected engineering work

Categorised for recruiters. Professional delivery stays separate from research mocks, academic coursework, and personal products.

Professional Delivery

Digital Banking Backend & DFCC API Support

Java/Spring Boot services and investigation work for digital banking API flows.

Overview

Professional delivery on banking APIs covering payment and fund-transfer flows, account retrieval, transaction history, exchange rates, and error handling. Prepared root-cause notes, SQL checks, Jira updates, log evidence, and release-support findings. No proprietary system ownership is claimed.

Technologies

JavaSpring BootREST APIsOracle SQLJPA / HibernatePostmanLinux

Challenges

  • Isolating faults across Java services, middleware, and core-banking response behaviour.
  • Producing evidence that BA, QA, and bank-side stakeholders can act on quickly.
  • Balancing release windows with careful verification.

Engineering decisions

  • Investigate from reproducible evidence: logs, payloads, correlation references, SQL checks, and API timing.
  • Document root cause clearly instead of relying on verbal hand-offs.
  • Treat middleware timeouts and slow core calls as first-class investigation targets.

My contribution

  • Backend API development and maintenance for banking workflows.
  • SIT/UAT and production-related issue investigation.
  • Technical documentation and release-support findings.

Architecture

Layered Spring Boot services exposing REST endpoints, with SQL-backed data access and integration through middleware toward core-banking systems. Investigation workflow combines Java logs, Spider logs, Oracle checks, and request/response comparison.

Research & Development

CBS/T24 Mock Server & Spider Performance Testing

Configurable mock environment for integration testing, latency experiments, and timeout analysis.

Overview

Engineering mock environment developed and used for integration testing, API validation, performance experiments, timeout analysis, and software engineering research. Not a production banking system. Does not imply ownership of Temenos T24, DFCC systems, or any client Core Banking System.

Technologies

PythonDockerAPI replayLatency / load testingLinux

Challenges

  • Recreating capacity, latency, and overload behaviour without touching production systems.
  • Making timeout evidence reproducible for middleware discussions.

Engineering decisions

  • Use a configurable mock rather than speculative production claims.
  • Drive experiments from log-derived payloads and route-specific profiles.

My contribution

  • Built and used mock endpoints for Spider timeout analysis and throughput checks.
  • Supported core-banking performance discussions with measurable evidence.

Architecture

Python-based mock server with configurable latency and overload profiles, used alongside Linux tooling to study middleware read-timeout behaviour under controlled conditions.

Featured

Case study

Smart AAC — Trilingual Assistive Communication

Offline-first Flutter AAC for Sinhala, Tamil, and English with on-device supportive FER.

Case studyGitHub

Overview

Final-year research and development project: a supportive Android AAC system for Sri Lankan children with communication difficulties. Combines trilingual communication cards, text-to-speech, caregiver customisation, and privacy-preserving on-device facial expression recognition framed as observation support—not diagnosis. Collaboration interest from Pragathi Centre / National Hospital Galle is supported by a formal letter; wider clinical deployment and pilot study remain subject to ethical clearance. No children were recruited for clinical evaluation in the reported study.

Technologies

FlutterDartTensorFlow LiteEfficientNetB0MobileNetV2Offline-first storageTTSSinhala / Tamil / English

Challenges

  • Designing AAC that treats Sinhala, Tamil, and English as first-class languages.
  • Keeping core features usable offline on typical Android phones.
  • Positioning FER safely with uncertainty states instead of forced labels.
  • Staying within ethical boundaries for clinical collaboration and child data.

Engineering decisions

  • Offline-first Flutter architecture with local vocabulary and no camera-frame upload.
  • Primary EfficientNetB0 TFLite model with MobileNetV2 fallback.
  • Separate companion app path for caregiver-customisable cards.
  • Explicit uncertain / no-face / unclear states in the emotion layer.

My contribution

  • End-to-end design, implementation, testing, and thesis documentation.
  • Model training/export pathway and mobile verification evidence.
  • EICON 2026 full paper (FPC21) with camera-ready revision after peer review.

Architecture

Layered Flutter app: presentation screens, services (storage, offline signal, sensory feedback, supportive audio), compiled trilingual vocabulary data, and bundled TFLite models. Companion simple_aac_app covers caregiver customisation, backup, restore, and sharing. No Firebase backend in the submitted build.

Personal Products

Yasaboy.com — Local-first Browser Tools

Public platform of 100+ client-side tools with privacy-first browser processing.

Demo

Overview

Product website for a local-first browser tools/PWA platform covering PDFs, documents, media, developer utilities, Sinhala typing, QR/barcode tools, and daily workflows. Distinct from this professional portfolio at portfolio.yasaboy.com.

Technologies

JavaScript / TypeScriptStatic webPWACloudflare PagesBrowser APIs

Challenges

  • Keeping tools useful without a backend for supported utilities.
  • Maintaining offline/PWA behaviour and a coherent multi-surface platform.

Engineering decisions

  • Process files in the browser where possible for privacy.
  • Static hosting with iterative documentation and tool structure.

My contribution

  • Product planning, architecture, implementation, deployment, and ongoing improvement.

Architecture

Static/PWA front door routing to tools, labs, docs, and experiments. Client-side processing for supported utilities; service-worker offline behaviour after first load.

Academic Projects

Personal Finance Tracker

University software engineering project for income, expenses, goals, and reporting.

GitHub

Overview

Academic project developed as a university software engineering assignment to demonstrate full-stack web application development. Enables users to manage personal income, expenses, savings goals, budgeting, and financial reporting. Not a commercial client project.

Technologies

PHPMySQLJavaScriptTailwind CSSChart.jsTCPDFPHPMailer

Challenges

  • Covering authentication, CRUD financial flows, analytics, and PDF reporting in one academic codebase.

Engineering decisions

  • Responsive dashboard with chart-based analytics and PDF export.
  • Verification and password-reset email support for account flows.

My contribution

  • Full-stack implementation of authentication, transactions, budgets, goals, dashboard, and reporting.

Architecture

PHP/MySQL server-rendered application with JavaScript charts, Tailwind styling, and PDF/email helpers.

Personal Products

Flutter Mobile Apps Portfolio

Android/mobile experiments across notes, games, reviews, and localisation.

GitHub

Overview

Android/mobile project work including book-review experiments, game prototypes, Sinhala notes/utilities, and APK-oriented Flutter builds. Demonstrates Flutter structure, packaging, localisation, and mobile-first product thinking.

Technologies

FlutterDartAndroidLocalisationLocal storage

Challenges

  • Shipping multiple small mobile experiments with consistent project structure.

Engineering decisions

  • Separate UI screens, widgets, and services for maintainable Flutter layouts.
  • Prefer APK-oriented builds for practical device testing.

My contribution

  • Design and implementation of multiple Flutter/Android experiments published on GitHub.

Architecture

Flutter apps with screen/widget/service separation, local storage, and Android packaging.